AGND, sometimes called SGND (signal ground), is the ground connection that the other, usually very calm, signals use as a reference. This includes the internal voltage reference needed for the regulation of the output voltage. Soft start and enable voltages are also referenced to …
通过分割层传输信号的其它方法是使用光隔离器(通method is a weighing scale where high-resolution (≥20-bit) 过光)、变压器(通过磁场)或者一个真正的差动信号(信号沿一条线路传输,然后在另一条线路上返回,无需返回电流接地)。 一种更好的方法是“分区”。 仅使用一个接地层始终为首选,把PCB划分为模拟部分和数字部分(参见图4b)。 模拟信号必须安排在板的模拟部分,而数字信. (ADC)。 a return path directly underneath each of the traces, pro-ducing a very small loop area.
Confusion about mixed-signal grounding has increased since designers started applying single-card grounding concepts to multicard systems. In systems having several data converters on different PCBs, the analog and digital ground planes are connected at several points, creating the possibility of ground loops and making a single-point
Part 1 explains typical terminologies and ground planes and introduces partitioning methods. Part 2 explores techniques for splitting the ground planes, including pros and cons. It also explains grounding in systems with multi-ple converters and multiple boards. Part 2 will appear in a future issue of Analog Applications Journal.